The present invention relates to a component mounting apparatus for mounting electronic components onto circuit boards.
Component mounting apparatuses for mounting electronic components onto boards to produce component-mounted boards are required to implement such stable operation as will prevent occurrences of apparatus faults due to operational errors of the apparatus or human errors or the like.
Arrangement of a prior art example of such component mounting apparatuses is shown in FIG. 5. This component mounting apparatus 40 comprises: a transfer section 42 for transferring to a specified position a circuit board 43 onto which components are to be mounted; a feed section 41 for feeding to a specified position a component 44 which is to be mounted onto the circuit board 43; an X-Y robot 47 equipped with a head 45 having a suction nozzle 49 for sucking up the component 44 from the feed section 41 and mounting it onto the circuit board 43 and with a board recognition camera 46 for the positioning of a mounting position; and a nozzle station 50 for storing a plurality of suction nozzles 49 corresponding to a plurality of components 44.
In this arrangement, the circuit board 43 is transferred to a specified mounting position by the transfer section 42. In order to load to the head 45 a suction nozzle 49 corresponding to the component 44 to be mounted, the X-Y robot 47 moves the head 45 to a location above the nozzle station 50, separates the currently loaded suction nozzle 49 from the head 45, and then loads to the head 45 a suction nozzle 49 matching the component 44 to be next mounted. Next, the X-Y robot 47 moves the board recognition camera 46 to a location above the circuit board 43 and measures a board mark 51 provided on the circuit board 43, thus accomplishing an operation of recognizing the mounting position. Subsequently, the X-Y robot 47 moves the head 45 to the feed section 41, sucks up the fed component 44 by the suction nozzle 49, and moves the head 45 to a location above the mounting position on the circuit board 43. In this operation, the suction posture in which the component 44 is sucked up by the suction nozzle 49 is recognized by a component recognition camera 52. Based on this component posture information, an operation of correcting the suction posture is performed, and the component 44 is mounted at the specified position on the circuit board 43.
In production processes with the component mounting apparatus as described above, it can occur that the operation of the apparatus is stopped due to the state of the apparatus, mis-feedings of components, and the like. When the apparatus is restarted after such a temporary stop, there are some cases where an unmounted component remains stuck to the suction nozzle due to residual pressure of the vacuum of the suction nozzle. In this state as it is, if a switching operation of the suction nozzle is executed, the component would enter the pocket of the nozzle station, causing the apparatus to be damaged.
The suction nozzle for sucking up abnormal-shaped components or small-sized components such as connectors and transformers with less area of flat surfaces is more likely to suffer suction errors due to clogging with dust or the like, so that the maintenance of the suction nozzle needs to be exercised on demand. The operator would take out the suction nozzle from the apparatus and, after cleaning it, accommodate it to the apparatus. In this process, there may occur human errors such as mis-positioning in returning the suction nozzle. Because the suction nozzle is controlled by a controller that controls the operation of the component mounting apparatus, a mis-positioning in returning the nozzle by the operator would, in some cases, cause the component mounting apparatus to be damaged due to inconsistency with the controlling operation of the apparatus.
Besides the above disadvantages, the number of kinds of suction nozzles has been increasing with diversified components to be mounted so that frequent changeovers of suction nozzles are needed in the production of one circuit board. As a result, there has arisen a demand for a stable operation that ensures a reliable execution of the control of suction nozzles.